<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<input type="text" value="123">
<input type="text" value="122">

<select id="select">
    <option value="+">+</option>
    <option value="-">-</option>
    <option value="*">*</option>
    <option value="/">/</option>
</select>
</body>
<script type="text/javascript">
    var txt = document.getElementsByTagName("input");
    console.log(txt[0].value);

    var select = document.getElementById("select");
    console.log(select);

</script>
</html>